Affected Animals:

This surgery is typically performed when the dog is approximately six months old, but can be done before or after this time. Older dogs usually require more extensive preoperative testing to assess the risk of anesthesia complications.

Overview: Ovariohysterectomy is the surgical removal of the ovaries and uterus. Known more commonly as a spay procedure, the surgery is performed on many female dogs. The indications for the procedure include preventing unwanted litters of puppies and the nuisance of repeated heat cycles; decreasing the probability of mammary or breast cancer; and in treating many reproductive tract disorders, including most commonly pyometra infection within the uterus, and uterine neoplasia.  Spaying a dog before her first heat cycle decreases the chances of mammary cancer by greater than 90 percent. The surgery is more difficult when the dog is in heat or pregnant, as both of these conditions result in increased uterine size and blood supply.

Description:

The surgery is performed under general anesthesia so that the dog is completely unconscious. An incision is made into the abdominal cavity to allow access to the entire reproductive tract. Each ovary is loosened from its attachment near the kidney and double-ligated, or tied off with two separate sutures. The tissue is transected or cut with a scalpel blade and observed for bleeding. The ligaments of the uterus are detached and the uterus is double-ligated just above the cervix. This tissue is cut and examined for bleeding. Before closing the surgery site, all ligatures or sutures are checked again to ensure that there is no bleeding. The abdominal incision is then closed in three layers. The internal muscle layer, the subcutaneous tissue, and outer skin are all sutured separately. Absorbable sutures are used internally and dissolve on their own.

Some veterinarians select skin sutures that are nonabsorbable, requiring a suture removal appointment seven to 14 days following the surgery so that they will be able to evaluate the incision. Other veterinarians elect to close the skin with absorbable suture and skin glue, which does not require a return visit to the veterinarian unless there are complications.

Prognosis:The prognosis is good for young, healthy dogs. If there are complications, the prognosis will depend upon the individual case.

Possible complications of ovariohysterectomy include hemorrhage, infection, recurrent estrus cycles due to the inadequate removal of the ovarian tissue, body weight gain if diet and exercise are not monitored, accidental ligation of a tube leading from the kidney to the urinary bladder called a ureter, and urinary incontinence due to the lack of estrogen. Other complications that can be seen with any abdominal surgery include anesthetic problems, suture reactions and infections, delayed wound healing or breakdown, self-inflicted trauma, and seroma, or blood-tinged fluid accumulation at the surgery site.

Most of these can be prevented by careful surgical technique and proper postoperative care. If the proper precautions are taken, the risk of complications is minimal. If complications do occur, however, the veterinarian should be notified promptly. Dehiscence, or separation of the incision layers, can be an emergency situation requiring surgery to replace abdominal contents. Dogs can chew out their sutures and cause great damage to the abdominal organs in a very short period of time.

The veterinarian will determine the appropriate treatment for any complication that may occur. Some examples of treatments include controlling bleeding by exploring the surgery site and ligating the leaking vessel; draining the fluid from a seroma and applying a pressure bandage; and providing hormone supplements to control hormonal urinary incontinence.

Preprocedure Care:

All surgical patients should receive a preoperative examination by the veterinarian. Dogs that are in their heat cycle may have the surgery postponed until the cycle is over. If the dog is an older animal, the veterinarian may take blood tests and possibly chest x-rays to check for any underlying diseases.

Postprocedure Care:

Most dogs are extremely tolerant of pain and show no signs of discomfort from the procedure. Unfortunately, as a result, they may attempt to resume their normal level of activity immediately after surgery, and this puts them at risk for complications. Strict monitoring is important. The dog should not be allowed off the leash for seven to 14 days after surgery, and should be prevented from licking the incision, running, jumping, and climbing stairs. Outdoor dogs should be kept inside for two weeks. The incision should be checked daily for any signs of swelling, redness, or heat. If the dog tries to lick the incision, an Elizabethan collar or similar device can be used to prevent the behavior.

Prevention:
Preventing complications involves daily inspection of the incision, preventing the dog from licking the surgery site, and keeping its activity level to a minimum for a period of seven to 14 days following the surgery. Any problems should be brought to the veterinarian's attention as soon as possible.